This invention relates generally to automatic coffee making and dispensing machines, and more particularly concerns an improved type of automatic coffee making and dispensing machine wherein hot water is directed downwardly through fresh coffee grounds held in a filter assembly and where the resulting liquid coffee is collected in a reservoir and maintained at a desired elevated temperature for subsequent dispensing in individual servng cup amounts.
Automatic coffee machines of the type to which this invention relates generally have an upper portion in which a cloth or paper filter assembly is held and a lower portion incorporating a single tank for receiving the resulting hot coffee which flows from the coffee grounds and through the filter assembly to the tank below.
Such automatic machines are used in large-scale food serving and preparing operations such as in restaurants, cafeterias, fast-food service facilities, and the like.
If only one coffee making machine is used in a food service facility, a second batch of coffee cannot be made in that machine until the first batch in that machine is used up or otherwise disposed of. Consequently, if only one such machine is used, there is a period of time after a first batch of coffee has been completely dispensed before the next batch of coffee is brewed and ready for serving. Consequently, to avoid this problem, food service facilities frequently have had to install two or more such coffee making machines so that one machine may be brewing a batch of coffee while the other one is used for holding and dispensing a batch of already brewed coffee. This of course is disadvantageous from the standpoint of the capital investment required to purchase more than one machine, from the standpoint of increased facility space required to accommodate more than one machine, and from the standpoint of increased labor required to maintain, operate, and clean the many parts associated with more than one machine.
Another problem with using a coffee making machine in a food service facility is that the capacity of the machine must be large enough to handle the peak capacity requirement (typically during meal times or coffee break times) and that at the non-peak capacity times, more coffee is frequently made and held for serving than is really necessary. One solution to this problem is to provide in a food service facility, in addition to one or more large coffee making machines, one or more smaller coffee making machines for use during the off-peak capacity times. This, of course, is disadvantageous from the standpoint of increased capital investment, increased labor, etc.
Another problem with many coffee making machines in use in food service facilities is that the facility staff must be relied upon to remember to remove the used coffee grounds from the coffee machine after the initial brewing of the batch of coffee has been completed in order to prevent drippings of the coffee grounds from falling into the batch of coffee below. This is important because drippings from coffee grounds are generally very concentrated with coffee ground residue and can add an undesirable, bitter component to the brewed coffee.
Another problem with many coffee making machines is that the brewed coffee can sit in the holding reservoir for many hours and there is no automatic way of alerting the food service facility staff as to how long the brewed coffee has been held in the machines. It has been found that coffee that has been held for a long period of time is not as fresh as newly brewed coffee and does not taste, to many people, as good as newly brewed coffee. Consequently, if an operator (waiter, waitress, etc.) does not know how long coffee has been held in the coffee machine, it is likely that coffee may be served which is not as good as freshly brewed coffee.
It would be desirable to dispose of coffee that has been held too long in a coffee machine and to brew a new batch of coffee after some predetermined time period in order to maintain an acceptable taste quality of the coffee. With many conventional coffee making machines, such a program can be undertaken only if the operators are conscious of this situation and are able to keep track of the time at which the various batches of coffee were first brewed. This of course is difficult in food service facilities where the staff changes throughout the day owing to a number of specific work shifts.
In view of the above described disadvantages found in many of the coffee making machines in use today, it would be desirable to provide a single machine which would take up a minimum amount of food service facility space and which would have the capacity for brewing one batch of coffee while holding another brewed batch of coffee for immediate use.
It would also be desirable to provide such a machine with features that would allow it to brew a substantially smaller batch of coffee for use during the off-peak capacity hours.
It would be beneficial if such a machine would also have automatic signalling or alarm devices to alert the operator when the coffee brewing cycle had been completed so that the used coffee grounds could be removed.
Additionally, it would be helpful if signals or alarms were provided for alerting the operator when the brewed coffee had been held in the coffee machine longer than some predetermined time period so that the operator would know to brew a new batch of coffee and to empty the "stale" batch of coffee.
It would also be desirable to provide a secondary grounds catching assembly below the usual filter assembly to prevent spent grounds from entering the finished brew and causing a bitter aftertaste in the coffee because of overextraction. Such a grounds catching assembly would also prevent the brewed coffee dispensing piping and faucet valves from being plugged up by such grounds.